Edward a



(Numdam y E.,A. TUTTLE.

, HOT AIREURNAGE. y No. 311,153. l PatentedJan. 20,1885.

@yew/Zar.

UNITED STATES EDWARD A. TUTTLE,

i PATENT OFFICE,

OF NFNV YORK, N. Y.

HOT-AIR FURNACE.

SFECIFICATIOKN forming part of Letters Patent No. 311,153, dated January 20, 1835. Application filed Novemberlfl, 1883. (No model.)

To all whom' t nasty concern Be it known that I, EDWARD A. TU-frfrLE, a citizen of the United States, residing at New York city, in the county and State of Newy York, have invented new and useful Improvements in Hot-Air Furnaces, oi' which the ifollowing is a specification.

My invention consists of improved arrange` ments of the fire-box and grate of a hot-air or other furnace for heating purposes, designed to improve the combustion and increase the radiation of the heat, the said improvements being a continuance whereby prop'ortionately` larger area of radiating-surface is obtained for 'a given amount of grate-surface than in other furnaces, and a bettermeans of effecting a properly-distributed supply of air above the nre-bed for the combustion of the gases is obtained; and it also consists of a duplex arrangement of the fire-box, whereby a part of the tire-box may beused independently of the other part when the whole capacity is not needed, and the whole may be used when so required, alias hereinafter fully described, reference being made to the accompanying drawings, in which- Figure 1 is a transverse sectional elevation of my improved furnace, Fig. 2 is a plan view of the grate and fire-box. Fig. 3 is a section with an air-inlet through the bottom of the lire-box.' Fig. i is a vertical section showing a modified form of the grate.`

,I construct the body a of the furnace in the lower portion, and the fire-box b in oblong form in'horizontal section, and arrange the grate c along the two long sides of the nrebox, said grate extending the whole length of said sides, but' only extending a short distance toward the center of the fire-box, and preferably being arranged in the steep inclines represented in Fig. 1, but it .may be h'orizontal, the grate and the sides of thefire-bor'c being thus extended and the breadth of the grate diminished, so that much larger heatingsurface of the tire-bon is exposed to the air and a much larger proportion of the fire iinpinges upon the heatii'ig-surface, so that with the increased area oi" heating-surface and the more intimate and extended distribution'of 5o the heat produced upon the said heating-surfaces much better results will probably be gained in respect of economy of coal and the heating-power ofthe furnace.

Another important,advantage of the disposition of the tire in narrow breadth and great length along the furnace-plate is the facility it affords for the introduction of oxygen above the lire-bed for the combnstionof the carbonio oxide, in the necessary equal distribution to effect the intimate contact and uniform adi'nixture for affording ,the lrequisite supply throughout the whole space without an overthrough which the air is-distributed to theV thin Ivolumes of gas, so as to supply the same with freshoxygen in much greater proportion' to the whole volume of gas than when the body of the iire is thicker, and the whole interior space is I,filledwith gas to which the requisite aniouniiif'of air lfor said interior cannot penetrate without being in too large volume for the gasin the nearer space, and thereby chilling it, and thus preventing its combustion. The space back of the fire-grate is to serve as a magazine for the supply of coal to the grate by descending theinclines f of the A-shaped middle imperforate section of the bottom of the lire-box, which l provide for the purpose, said inclines descending to the level `of the lower' ends of the grate-bars, or thereabout, but terminating a suitable distance therefrom to allow a door, g, to be introduced for opening sufficiently to allow the clinkers to be raked out from below and for dumping the whole contents of the fire-box when required.

The doors are fixed on apivot-shaft, h, having suitable bearings at the ends of the rebox, and'having a crank, j, at one end,suit ably prolonged to project beyond the inclosing-wall of the furnace,for use in working the doors. The cranlrs will be supported by hooks or other means to hold up the doors, and the grates will in practice have bearings at the ends, allowing them to be shifted lengthwise I OO to shake the fire. In this example I have represented a double arrangement of the furnace-that is, a tire-grate along each sidewhich is the most desirable; but it is to be understood that the grate may be limited to one side only, when less heating-power will serve, and in such case the bottom f will have only one incline, and said bottom will be extended up to the side wall of the fire-box not having the grate. The air is tobe allowed to circulate ireely under the bottom f, for being heated, and for cooling the bottom for its protection, and for supplying air to the gases above the coal-bed.` rlhe ash-chambers 7c una double iire may be made on both sides, ac-v cording to the amount of fire required, and the separation of the two grates by the bottom f is such that iire will not communicate `from one side to the other, particularly as with separated ash-pits, as here represented, one

' may be closed to cut off the air-supply.V The air-inlet passage p through the apex of the imperforate bottom f may be extended to the top ofthe tire-bed, or thereabout, to Vprevent the issue of the air below the surface of the Ynre-bed, and a cap, q, may be placed overthe passage p,to prevent ashes fromfalling through into the air-space s below. This passage p may be used alone or together with the inlets e for the supply ofair to burn the-gases above the coal-bed. In some cases it maybe preferred to dispense with the inlets e, to avoid the possibility of gases escaping through them into the air to be heated.

I am aware of the patent to Hershey, No. 189,218, in which there is a A-shaped middle section of the-fire-grate a part of which is imperi'orate, butth atis notacontrivance oftwo grates in one fire-box separated/by an imperforate Ashaped bottom adapted to maintain a re on one side only, because the air passing through said middle section, either the sides or top, will cause combustion over the whole grate, whereas the imperforate bottom of my contrivance is adapted to separate the two door g, below or inside of the tire-grate, and

the sloping bottom f ofthe nre-box back of the door, substantially as described.

2. In a heating-furnace, the tregrates c, arranged along and projecting inward from the opposite sides of the fire-box, in combination with a door, g, below or inside of-each grate, and with the inverted-V-shaped bottom f, arranged between said grates and doors, substantially as described.

3. In one and the same fire box or chamber, two separate re-grates separated bythe shaped imperforate bottom, substantially as described.

In witness whereof I have hereunto signed my name in t-he presence of two subscribing witnesses. y

EDVARD A. TU'ITLE.

Vitnesses:

XV. J. MORGAN, S. II. MORGAN.

It is hereby certified that in Letters Patent No, 311,153, grunted J :1n nary 20, 1885, upon the application of' Edward A. Tuttle, of New York, New York, for :tn improvement in Hot-Air Furnaces," nn error appears in the printed specification 'requiring the followiu correction viz: Inline 13 u e l the word continuance should read g a P g y contrivance; a-nd that the Letters Patent should be read with this correction therein to make it conform to the record of the oase in the Patent Oiice.

Signed, counter-signed, and sealed this 10th day of February, A. D. 1885.

M. L. JOSLYN, Acting Secretary of the Interior.

[SEAL] Countersigned:

BENJ. BUTTERWORTH,

Cmnnssoner of Patents. 

